non native invasives

A visitor to the Extension Master Gardener office told me he had a plant to identify that was too big to bring inside—that got my interest. In the back of his truck he had a grass-like plant over 10 feet tall with hollow stems!

 Bamboo or river cane?

I was looking at either a running type of bamboo (Phyllostachys spp.) or another form of bamboo: river cane (Arundinaria spp.). The difference between the two? One is an extremely aggressive invasive native and the other is a native.

 Phyllostachys aurea is a bamboo species of the ‘running bamboo’ type. It is commonly known by the names fishpole bamboo and golden bamboo.  This is the species most widely seen in the landscape. A related species is Phyllostachys nigra—black bamboo—is also widely cultivated and invasive! They both form dense—almost impenetrable—thickets that crowd out all other plants.

Arundinaria is the only bamboo native to North America, found in the south-central and southeastern United States. It is tree-like, growing to heights up to 26 ft. It has distinctive fan-like cluster of leaves at the top of new stems called a top knot. Arundinaria gigantea, commonly known as river cane, is a woody plant native to North Carolina.  River cane communities occur on floodplains, bogs, along streams and rivers and in riparian woods.

It became obvious to me that my visitor just wanted it gone from his yard!

Dr. Joseph C. Neal, Department of Horticultural Science, at NC State University, discusses three techniques for dealing with bamboo in the publication “Controlling Bamboo in Landscape Plantings.”

Removal

To eliminate a planting completely requires physically removing as much of the top growth and root mass as possible—this will require power equipment for large infestations! Bamboo will regenerate from any small rhizomes left behind so long-term follow-up will typically require the use of herbicides or planting the area in lawn:

• Chemical control involves spraying with a post-emergent, non-selective herbicide such as glyphosate and may require repeated spraying whenever new growth occurs.
• Convert to lawn avoids the use of herbicides and relies on the fact that bamboo will not tolerate frequent mowing. This works only if you mow the entire area! If you don’t eliminate the entire stand, new shoots will keep moving in from the remaining plants.

Containment

• If you want to contain a bamboo planting, you can install a barrier— concrete, metal, plastic, or pressure-treated wood—installed at least 18 inches deep that slants outward and rises at least a couple of inches above the ground. Because barriers only deflect rhizomes rather than prevents them from growing, you will need to inspect the barrier at least yearly to remove any new rhizomes.

Regardless of which method of control you choose, eradicating a bamboo infestation requires intensive effort over several years.  Of course, the best way to prevent bamboo from becoming a weed is to avoid planting the invasive, spreading-type bamboos in the first place—and ask your neighbors to avoid it, too!

 Article by Bob Wardwell, Extension Master Gardener^SM Volunteer

Controlling bamboo in landscape plantings:

https://content.ces.ncsu.edu/controlling-bamboo-in-landscape-plantings

Identifying Native Bamboo: www.namethatplant.net/article_nativebamboo.shtml

More about river cane:

http://www.indefenseofplants.com/blog/2017/6/26/north-americas-native-bamboos